U.S. patent application number 15/723138 was filed with the patent office on 2019-04-04 for method, apparatus and system for fingerprint identification.
This patent application is currently assigned to Novatek Microelectronics Corp.. The applicant listed for this patent is Novatek Microelectronics Corp.. Invention is credited to Chun-Yen Lin, Chia-Sheng Nien.
Application Number | 20190102600 15/723138 |
Document ID | / |
Family ID | 65897232 |
Filed Date | 2019-04-04 |
United States Patent
Application |
20190102600 |
Kind Code |
A1 |
Lin; Chun-Yen ; et
al. |
April 4, 2019 |
METHOD, APPARATUS AND SYSTEM FOR FINGERPRINT IDENTIFICATION
Abstract
A fingerprint identification apparatus includes a force sensor,
a fingerprint sensor, and a switching circuit coupled between the
force sensor and the fingerprint sensor. The switching circuit is
configured to alternately activate a low power force detection mode
to detect the force touch using the force sensor and a low power
fingerprint detection mode to detect the finger touch using the
fingerprint sensor after a switching period. In response to
determining that either the force touch or the finger touch is
detected, the fingerprint identification apparatus detects the
fingerprint using the fingerprint sensor in a normal fingerprint
detection mode. Next, the fingerprint identification apparatus
determines whether the detected fingerprint matches one of
reference fingerprints, and outputs an interrupt signal indicating
whether the detected fingerprint matches one of the reference
fingerprints. A fingerprint identification method and a system for
fingerprint identification are also introduced.
Inventors: |
Lin; Chun-Yen; (Hsinchu
County, TW) ; Nien; Chia-Sheng; (Hsinchu City,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Novatek Microelectronics Corp. |
Hsinchu |
|
TW |
|
|
Assignee: |
Novatek Microelectronics
Corp.
Hsinchu
TW
|
Family ID: |
65897232 |
Appl. No.: |
15/723138 |
Filed: |
October 2, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 1/3262 20130101;
G06K 9/00087 20130101; G06K 9/0002 20130101; G06F 3/0414
20130101 |
International
Class: |
G06K 9/00 20060101
G06K009/00; G06F 3/041 20060101 G06F003/041; G06F 1/32 20060101
G06F001/32 |
Claims
1. A fingerprint identification method of a fingerprint
identification apparatus, comprising: alternately activating a low
power force detection mode to detect a force touch using a force
sensor and a low power fingerprint detection mode to detect the
finger touch using the fingerprint sensor after a switching period;
and in response to determining that either the force touch or the
finger touch is detected, detecting the fingerprint using the
fingerprint sensor in a normal fingerprint detection mode,
determining whether the detected fingerprint matches one of
reference fingerprints, and outputting an interrupt signal
indicating whether the detected fingerprint matches one of the
reference fingerprints.
2. The fingerprint identification method according to claim 1,
wherein the low power force detection mode is deactivated when the
low power fingerprint detection mode is activated, and the low
power fingerprint detection mode is deactivated when the low power
fingerprint detection mode is activated.
3. The fingerprint identification method according to claim 1,
wherein the switching period is adjustable.
4. The fingerprint identification method according to claim 1,
wherein a threshold for detecting the finger touch in the low power
fingerprint detection mode is lower than a threshold for detecting
a finger touch in the normal power fingerprint detection mode.
5. The fingerprint identification method according to claim 1,
further comprising: waking up a processor of a portable electronic
device in response to determining that the interrupt signal is
outputted, wherein the interrupt signal is either a first interrupt
signal or a second interrupt signal, the first interrupt signal
indicates that the fingerprint is detected and matched one of the
plurality of reference fingerprints, and the second interrupt
signal indicates that the fingerprint is not detected or the
detected fingerprint is not matched one of the plurality of
reference fingerprints.
6. The fingerprint identification method according to claim 5,
further comprising: when the first interrupt signal is outputted,
allowing the processor to execute a first set of actions in an
unlocked state of the portable electronic device; and when the
second interrupt signal is outputted, allowing the processor to
execute a second set of actions in a locked state of the portable
electronic device, wherein the second set of actions is a subset of
the first set of actions.
7. The fingerprint identification method according to claim 5,
wherein the force touch is a non-finger touch which is not induced
by a human's finger.
8. A fingerprint identification apparatus, comprising: a force
sensor, configured to detect a force touch applied to the force
sensor; a fingerprint sensor, configured to detect a finger touch
and a fingerprint; and a switching circuit, coupled between the
force sensor and the fingerprint sensor, configured to alternately
activate a low power force detection mode to detect the force touch
using the force sensor and a low power fingerprint detection mode
to detect the finger touch using the fingerprint sensor after a
switching period, in response to determining that either the force
touch or the finger touch is detected, the fingerprint
identification apparatus detects the fingerprint using the
fingerprint sensor in a normal fingerprint detection mode,
determines whether the detected fingerprint matches one of
reference fingerprints, and outputs an interrupt signal indicating
whether the detected fingerprint matches one of the reference
fingerprints.
9. The fingerprint identification apparatus according to claim 8,
wherein the switching circuit is further configured to deactivate
the force sensor when the fingerprint sensor is activated in the
low power fingerprint detection mode, and to deactivate the
fingerprint sensor when the force sensor is activated in the low
power force detection mode.
10. The fingerprint identification apparatus according to claim 8,
wherein the switching period is adjustable.
11. The fingerprint identification apparatus according to claim 8,
wherein the fingerprint identification apparatus is an integrated
circuit.
12. The fingerprint identification apparatus according to claim 8,
wherein a threshold for detecting the finger touch in the low power
fingerprint detection mode is lower than a threshold for detecting
a finger touch in the normal power fingerprint detection mode.
13. The fingerprint identification apparatus according to claim 8,
wherein the interrupt signal is used to wake up a processor of a
portable electronic device, the interrupt signal is either a first
interrupt signal or a second interrupt signal, the first interrupt
signal indicates that the fingerprint is detected and matched one
of the plurality of reference fingerprint, and the second interrupt
signal indicates that the fingerprint is not detected or the
detected fingerprint is not matched one of the reference
fingerprints.
14. The fingerprint identification apparatus according to claim 13,
wherein the first interrupt signal allows the processor to execute
a first set of actions in an unlocked state of the portable
electronic device, the second interrupt signal allows the processor
to execute a second set of actions in a locked state of the
portable electronic device, and the second set of actions is a
subset of the first set of actions.
15. The fingerprint identification apparatus according to claim 8,
wherein the force touch is a non-finger touch which is not induced
by a human's finger.
16. A system for fingerprint identification, comprising: a memory,
storing program instructions corresponding to a first set of
actions and a second set of actions; a processor, coupled to the
memory, configured to execute the program instructions
corresponding to a first set of actions and a second set of
actions; and an integrated fingerprint identification circuit,
comprising: a force sensor, configured to detect a force touch
applied to the force sensor; a fingerprint sensor, configured to
detect a finger touch and a fingerprint; and a switching circuit,
coupled between the force sensor and the fingerprint sensor,
configured to alternately activate a low power force detection mode
to detect the force touch using the force sensor and a low power
fingerprint detection mode to detect the finger touch using the
fingerprint sensor after a switching period, in response to
determining that either the force touch or the finger touch is
detected, the integrated fingerprint identification circuit detects
the fingerprint using the fingerprint sensor in a normal
fingerprint detection mode, determines whether the detected
fingerprint matches one of reference fingerprints, and outputs an
interrupt signal to wake up the processor, and the processor
executes the first set of actions un an unlocked state or the
second set of actions in a locked state according to the interrupt
signal.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] This invention relates to a system, a method and an
apparatus for fingerprint identification, and particularly a lower
power consumption and small size fingerprint identification
apparatus, and a method for identifying fingerprint in low power
consumption.
2. Description of Related Art
[0002] Nowadays, many electronic devices have a power saving mode,
where a screen of the electronic device is turned off and/or a
processor of the electronic device is in a sleep mode to save power
consumption. A user of the electronic device may press a button
(such as a home button, power button or sleep/awake button) to
switch the electronic device from the power saving mode back to a
normal operating mode. However, the electronic device may be
unintentionally switched back to the normal operation mode by, for
example a non-finger object accidentally touching the button. Some
electronic devices are equipped with variety of sensors, but each
of the sensors are coupled to a dedicated pin of the processor and
the processor is always awake. Accordingly, power consumption must
be used to sustain the operation of the processor, and the
processor's pins are not used flexibly and effectively.
[0003] Therefore, there is a need for a fingerprint identification
method, apparatus and system that are capable of accurately
detecting a finger touch and a force touch, and identifying whether
the detected fingerprint is authenticated in low power
consumption.
SUMMARY OF THE INVENTION
[0004] The invention introduces a system, a method and an apparatus
for identifying fingerprint in low power consumption.
[0005] The fingerprint identification apparatus includes a
fingerprint sensor, a force sensor and a switching circuit. The
force sensor is configured to detect a force touch applied to the
force sensor. The fingerprint sensor is configured to detect a
finger touch and a fingerprint. The switching circuit is coupled
between the force sensor and the fingerprint sensor, and is
configured to alternately activate a low power force detection mode
to detect the force touch using the force sensor and a low power
fingerprint detection mode to detect the finger touch using the
fingerprint sensor after a switching period. In response to
determining that either the force touch or the finger touch is
detected, the fingerprint identification apparatus detects the
fingerprint using the fingerprint sensor in a normal fingerprint
detection mode. Next, the fingerprint identification apparatus
determines whether the detected fingerprint matches one of
reference fingerprints, and outputs an interrupt signal indicating
whether the detected fingerprint matches one of the reference
fingerprints.
[0006] The switching period may be adjustable, and the fingerprint
identification apparatus may be an integrated circuit (IC).
[0007] In an embodiment of the invention, the interrupt signal is
used to wake up a processor of a portable electronic device. The
interrupt signal is either a first interrupt signal or a second
interrupt signal. The first interrupt signal indicates that the
fingerprint is detected and matched one of the reference
fingerprints. The second interrupt signal indicates that the
fingerprint is not detected or the detected fingerprint is not
matched one of the reference fingerprints.
[0008] In an embodiment, the first interrupt signal allows the
processor to execute a first set of actions in an unlocked state of
the portable electronic device. The second interrupt signal allows
the processor to execute a second set of actions in a locked state
of the portable electronic device. The second set of actions is a
subset of the first set of actions.
[0009] The invention further provides a fingerprint identification
method which includes a step of alternately activating a low power
force detection mode to detect a force touch using a force sensor
and a low power fingerprint detection mode to detect the finger
touch using a fingerprint sensor after a switching period. In
response to determining that either the force touch or the finger
touch is detected, the fingerprint identification method detects
the fingerprint using the fingerprint sensor in a normal
fingerprint detection mode. Next, the fingerprint identification
method determines whether the detected fingerprint matches one of
reference fingerprints, and outputs an interrupt signal indicating
whether the detected fingerprint matches one of the reference
fingerprints.
[0010] The invention further provides a system for fingerprint
identification which comprises a memory, a processor and an
integrated fingerprint identification circuit. The memory stores
program instructions corresponding to a first set of actions and a
second set of actions. The processor is coupled to the memory and
is configured to execute the program instructions corresponding to
a first set of actions and a second set of actions. The integrated
fingerprint identification circuit includes a force sensor, a
fingerprint sensor and a switching circuit. The switching circuit
is coupled between the force sensor and the fingerprint sensor, and
is configured to alternately activate a low power force detection
mode to detect the force touch using the force sensor and a low
power fingerprint detection mode to detect the finger touch using
the fingerprint sensor after a switching period. In response to
determining that either the force touch or the finger touch is
detected, the fingerprint identification circuit outputs an
interrupt signal to wake up the processor, and the processor
executes the first set of actions or the second set of actions
according to the interrupt signal.
[0011] As per the aforementioned embodiments, the method, apparatus
and system for fingerprint identification may accurately identify a
fingerprint touch in low power consumption.
[0012] The following embodiments are provided along with
illustrations to facilitate the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 illustrates a schematic diagram of the fingerprint
identification apparatus according to an embodiment of the
invention.
[0014] FIG. 2 illustrates a schematic diagram of the fingerprint
identification system according to an embodiment of the
invention.
[0015] FIG. 3 illustrates a flowchart diagram of the fingerprint
identification method according to an embodiment of the
invention.
[0016] FIG. 4 illustrates a block diagram of the fingerprint
identification method according to an embodiment of the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The aforementioned illustrations and following detailed
descriptions are exemplary for the purpose of further explaining
the scope of the invention. Other objectives and advantages related
to the invention will be illustrated in the subsequent descriptions
and appended drawings.
[0018] FIG. 1 illustrates a schematic diagram of the fingerprint
identification apparatus 110 according to an embodiment of the
invention. The fingerprint identification apparatus 110 includes a
force sensor 112, a fingerprint sensor 114 and a switching circuit
116. The force sensor 112 is configured to measure forces applied
to the force sensor, thereby detecting a force touch (e.g.,
non-finger press) on the force sensor 112. It should be noted that
the force sensor 112 may be any types of force sensor, and the
fingerprint identification apparatus 110 may have more than one
force sensors 112. For example, the force sensor 112 may be a
semiconductor force sensor, but the invention should not be limited
thereto.
[0019] In an example, when a force touch or a press is applied to
the force sensor 112, a sensed value (e.g., a current, a voltage, a
capacitance change, etc) is outputted by the force sensor 112. This
sensed value may be compared to a threshold to determine whether
the force touch or the force touch is applied to the force sensor
112. The sensed value may be compared to a range of the thresholds
to determine the force level of the detected force touch. It should
be noted that the force sensor 112 may operate in either a low
power mode or in a normal mode, where the threshold or the range of
the thresholds in the low power mode is smaller than the
corresponding threshold or the corresponding range of the
thresholds in the normal mode. However, the invention is not
limited thereto.
[0020] The fingerprint sensor 114 is configured to sense a finger
touch and a fingerprint of a user. Types of fingerprint sensor 114
and the number of the fingerprint sensor 114 are determined
according to designed requirements. For example, the fingerprint
sensor 114 may be an optical fingerprint sensor, a capacitive
fingerprint sensor, an ultrasound fingerprint sensor, or a thermal
fingerprint sensor, but the invention is not limited thereto.
[0021] In an example, when a user's finger touches the fingerprint
sensor 114, a sensed value (e.g., a current, a voltage, a
capacitance change, a resistance change, etc) and a captured image
of the fingerprint may be obtained by the fingerprint sensor 114.
The sense value of the fingerprint sensor 114 may be compared with
a predetermined threshold to determine whether there is a finger
touch on the fingerprint sensor 114. The image of the fingerprint
captured by the fingerprint sensor 114 may be compared with images
of reference fingerprints to determine a similarity, thereby
determining whether the captured fingerprint is matched with the
reference fingerprints (e.g., similarity is greater than a
threshold). It should be noted that the fingerprint sensor 114 may
operate in either a low power mode or in a normal mode, where the
thresholds (e.g., predetermined threshold to determine finger
touch, and the threshold to determine the similarity of the capture
fingerprint and the reference fingerprints) in the low power mode
is smaller than the corresponding thresholds in the normal mode.
However, the invention is not limited thereto.
[0022] The switching circuit 116 is coupled between the force
sensor 112 and the fingerprint sensor 114. The switching circuit
116 is configured to alternately activate a low power force
detection mode to detect the force touch using the force sensor 112
and a low power fingerprint detection mode to detect the finger
touch using the fingerprint sensor 114 after a switching period. In
an embodiment, the switching circuit 116 may include a counter or a
delay circuit (not shown) to set the value of switching period. For
example, the force sensor 112 is initially activated in the low
power force detection mode to sense the force touch applied to the
force sensor 112. If no force touch is sensed by the force sensor
112, the delay circuit of the switching circuit 116 may delay the
clock for the switching period. When the switching period is up,
the switching circuit 116 activates the fingerprint sensor 114 in
the low power fingerprint detection mode to sense the finger touch
on the fingerprint sensor 114. If no finger touch is sensed by the
fingerprint sensor 114, the delay circuit of the switching circuit
116 delays the clock for the switching period. When the switching
period is up, the switching circuit 116 activates the force sensor
112 in the low power fingerprint detection mode again. It should be
noted that, when the force sensor 112 is activated during the low
power force detection mode, the fingerprint sensor 114 is
deactivated. When the fingerprint sensor 114 is activated during
the low power fingerprint detection mode, the force sensor 112 is
deactivated. The above process is iterated until a force touch or a
finger touch is detected by the force sensor 112 or the fingerprint
sensor 114, respectively. The switching period may be set to be
adjustable so as to avoid events to be missed (e.g., a non-finger
pressed is applied while the apparatus is during a fingerprint
detection mode). However, the invention is not limited thereto. The
switching period may be fixed.
[0023] In an embodiment of the invention, the fingerprint
identification apparatus 110 is packed in an integrated circuit.
Alternatively, the fingerprint identification apparatus 110 may be
a part of any circuits and systems.
[0024] FIG. 2 illustrates a schematic diagram of the fingerprint
identification system 200 according to an embodiment of the
invention. The fingerprint identification system 200 includes an
integrated fingerprint identification circuit 210 and a portable
electronic device 220. The portable electronic device 220 includes
a memory 222, a processor or a center processing unit (CPU) 224 and
a display 226.
[0025] The memory 222 is configured to store program instructions
corresponding to a first set of actions and a second set of
actions. The first set of actions may comprise actions,
applications that may be executed during an unlocked state of the
portable electronic device 220. For example, the first set of
actions may include all the applications and actions that are
supported by the portable electronic device. The second set of
actions may include actions, applications that may be executed
during a locked state of the portable electronic device 220 such as
an emergency call application, a mapping application, and a
notification application. In other words, the second set of actions
may be a subset of the first set of actions (all the actions of the
second set of actions are contained in the first set of
actions).
[0026] The memory 222, for example, RAM, flash memory, ROM, EPROM,
EEPROM, registers, hard disk, a removable disk, a CD-ROM, or any
other form of machine or computer readable storage medium. The
memory 222 may be coupled to the processor such that the processor
may read information from, and write information to, the memory. In
the alternative, the memory may be integral to the processor.
[0027] The processor 224 is coupled to the memory and is configured
to execute the program instructions corresponding to a first set of
actions and a second set of actions according to an interrupt
signal. The processor 224 may include a single processor or
multiple processors to perform the exemplary image processing
method, but the number of the processors does not limit the
invention. In the present embodiment, the processor is, for
example, a micro-controller unit (MCU), a central processing unit
(CPU), or other microprocessor, a digital signal processor (DSP), a
programmable controller, application specific integrated circuits
(ASIC), a programmable logic device (PLD), or other similar
devices.
[0028] The processor 224 may control operations of display 226. The
display 226 may be any types of the displays.
[0029] The integrated fingerprint identification circuit 210 is
electrically coupled to the portable electronic device 220. The
integrated fingerprint identification circuit 210 includes a force
sensor 212, a fingerprint sensor 214 and a switching circuit 216.
The force sensor 212, the fingerprint sensor 214 and the switching
circuit 216 shown in FIG. 2 are similar to the force sensor 112,
the fingerprint sensor 114 and the switching circuit 116 shown in
FIG. 1, thus the detailed description of force sensor 212, the
fingerprint sensor 214 and the switching circuit 216 are omitted
herein.
[0030] When either the force touch or the finger touch are detected
using the force sensor 212 and fingerprint sensor 214, the
integrated fingerprint identification circuit 210 may output an
interrupt signal Is to the portable electronic device 220 to wake
up the processor 224 and turn on the display 226. The subsequent
operations may be performed by the processor 224 according to the
interrupt signal and user's commands.
[0031] FIG. 3 illustrates a flowchart diagram of the fingerprint
identification method according to an embodiment of the invention.
Referring to FIG. 1 and FIG. 3, the fingerprint identification
apparatus 110 is alternately switched between the low power force
detection mode and the low power fingerprint detection mode after
the switching period. For example, in steps 302 and 304, the force
sensor 112 is activated in the low power force detection mode to
detect whether there is a force touch applied to the force sensor
112. If no force touch is detected by the force sensor 112, the
switching circuit 116 delays the clock for the switching period.
Afterward, in steps 306 and 308, the fingerprint sensor 114 is
activated in the low power fingerprint detection mode to detect
whether there is a finger touch is applied to the fingerprint
sensor 114. If no finger touch is detected by the fingerprint
sensor 114 in steps 306 and 308, the switching circuit 116 delays
the clock for the switching period, and then activate the low power
force detection mode again. The above process is repeated until
either a force touch or a finger touch is detected by the force
sensor 112 and the fingerprint sensor 114.
[0032] When a force touch or a finger touch in steps 302 to 308 is
detected, the fingerprint sensor 114 is activated in the normal
fingerprint detection mode to detect the fingerprint (step 310).
The threshold that is used to detect finger touches and
fingerprints in the normal fingerprint detection mode may be
greater than the corresponding threshold that is used to detect
finger touches and fingerprints in the low power fingerprint
detection mode.
[0033] In step 312, the detected fingerprint in steps 310 is
compared to at least one reference fingerprint to determine whether
the detected fingerprint matches the at least one reference
fingerprint. If the detected fingerprint matches the at least one
reference fingerprint, the fingerprint detection apparatus 110, in
steps 312 and 314, sends the first interrupt signal to a processor
(the processor 224 of the portable electronic device 220 shown in
FIG. 2) to wake up the processor and turn on the display (the
display 226 of the portable electronic device 220 shown in FIG. 2).
In response to receiving the first interrupt signal, the processor
224 may unlock the portable electronic device 220, and then
executes one or more actions in the first set of actions 3161 to
316n according to user's commands, where the actions 3161 to 316n
are supported by the portable electronic device 220 in the unlocked
state.
[0034] If the detected fingerprint does not match any one of the at
least one reference fingerprint, the fingerprint detection
apparatus 110, in steps 312 and 318, sends the second interrupt
signal to a processor (the processor 224 of the portable electronic
device 220 shown in FIG. 2) to wake up the processor and turn on
the display (the display 226 of the portable electronic device 220
shown in FIG. 2). In response to receiving the second interrupt
signal, the processor 224 may keep the portable electronic device
220 in locked state, and then execute one or more actions among the
second set of actions 3201 to 320n according to user's command. The
second set of actions 3201 to 320n may include an emergency call
application, a mapping application, and a notification application,
etc. The second set of actions 3201 to 320n may be a subset of the
first set of actions 3161 to 316n.
[0035] FIG. 4 illustrates a block diagram of the fingerprint
identification method according to an embodiment of the invention.
In step 402, the method alternately activates a low power force
detection mode to detect a force touch using a force sensor and a
low power fingerprint detection mode to detect the finger touch
using the fingerprint sensor after a switching period.
[0036] In step 404, in response to determining that either the
force touch or the finger touch is detected, the method detects the
fingerprint using the fingerprint sensor in a normal fingerprint
detection mode, determines whether the detected fingerprint matches
one of a plurality of reference fingerprints, and outputs an
interrupt signal indicating whether the detected fingerprint
matches one of the reference fingerprints.
[0037] In summary, the embodiments of the invention introduce a
system, a method and an apparatus for fingerprint identification in
low power consumption. The low power force detection mode and the
low power fingerprint detection mode are alternately activated
after the switching period to detect the force touch or the finger
touch with low power consumption. Since the processor and the
display are not waked up during the detection of the force touch
and the finger touch, the invention may further save power
consumption. The switching period between the low power force
detection mode and the low power fingerprint detection mode are set
to be adjustable so as to avoid the events (e.g., touches or
presses) to be missed. Additionally, the fingerprint identification
apparatus may be integrated in an integrated circuit (IC), thereby
reducing the size and power consumption of the fingerprint
identification apparatus. In this way, the system, the method and
the apparatus for fingerprint identification may accurately
identify the finger touch and fingerprint in low power
consumption.
[0038] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
invention without departing from the scope or spirit of the
invention. In view of the foregoing, it is intended that the
invention cover modifications and variations of this invention
provided they fall within the scope of the following claims and
their equivalents.
* * * * *